For more than a decade astrophysicists have wondered why nature appears to show an odd restraint in the way it slays stars. In life, they range from pip-squeaks to behemoths. Small ones simply burn out and fade away, but something more curious happens to the jumbo-size variety. When such a star dies, its great bulk causes its innards to implode as a core-collapse supernova. The process sparks a cataclysmic explosion and compresses some of the remains into astrophysical exotica—often a neutron star or, for the very heaviest suns, a black hole. Yet a pronounced rift appears to divide the weight classes of these two types of massive stellar corpses. Although astronomers have spotted neutron stars weighing up to around two solar masses and black holes as light as five, middleweight cadavers have gone entirely missing—until now.